1. Field of the Invention
The present invention relates to a golf club head. In particular, the present invention relates to a golf club head the weight of which is reduced for adjusting the center of gravity of the golf club head.
2. Description of Related Art
FIG. 1 of the drawings illustrates a typical golf club head 1 made of metal. The golf club head 1 includes a golf club head body 10, a striking plate 11, a heel 12, and a neck or hosel 13 to which a shaft (not shown) is mounted. The heel 12 connects the hosel 13 to the striking plate 11. The center of gravity 14 of the golf club head 1 is relatively close to the heel 12, as the heel 12 and the hosel 13 have considerable weights. Thus, the center of gravity 14 is not located in the sweet spot of the striking plate 11. As a result, the inertial moment of the golf club head 1 is reduced, and the momentum imparted from the golf club head 1 to the golf ball is thus reduced. The striking effect of the golf club head 1 is adversely affected accordingly.
U.S. Pat. No. 4,995,609 discloses an improvement in iron golf clubs in which a hollow hosel is provided to thereby reduce weight of hosel and bridge that can be redistributed to the blade to increase the momentum that can be imparted to a golf ball. In an embodiment of the U.S. Pat. No. 4,995,609, as illustrated in FIG. 2 of the drawings, the golf club head 1 includes a golf club head body 10, a striking plate 11, and a hosel 13 to which a shaft 15 is mounted. A step 101 is formed in a lower end of a heel 12 between the hosel 13 and the golf club head body 10 to reduce the weight of the hosel side, thereby shifting the center of gravity 14 toward the toe 16 of the golf club head 1; namely, outwardly away from the heel 12, thereby increasing the inertial moment of the golf club head 1 that would lead to improvement in the striking effect of the golf club head 1 (i.e., the flying distance of the golf ball). However, although the center of gravity 14 is shifted outwardly away from the heel 12 through provision of the step 101 of the golf club head 1, the step 101 adversely affects the structural strength of the heel 12 of the golf club head 1. Further, the weight of the lower portion of the golf club head 1 is reduced since the step 101 is located in the lower end of the heel 12. Thus, the center of gravity 14 of the golf club head 1 is not only shifted outwardly away from the heel 12 but also shifted upward. As a result, the sweet spot of the striking plate 11 is too high. Essentially, provision of the step 101 in the golf club head 1 neither improves the striking effect nor increases the inertial moment of the golf club head 1. Further, the possibility of breakage or twist of the golf club head 1 is increased.
U.S. Pat. Nos. 5,183,255; 5,230,510; 5,324,033; 5,377,978; 5,607,363; 5,626,528; and 5,643,105 disclose similar structures that include a recessed portion in either the heel or the hosel of the golf club head for shifting the center of gravity of the golf club head and thus have the same problems.